Barrel harmonics refers to the manner in which the barrel of a rifle or other firearm whips, torques and contorts when tiring. The point in time at which the bullet exits the barrel will determine the discharge orientation of the muzzle relative to its rest position prior to firing. If the bullet exits the muzzle near a peak or valley in the barrel motion, the muzzle will be relatively stationary at the instant when the bullet leaves the barrel, and shot dispersion will be minimized. Once the barrel reaches the upper or lower limit of its travel (crest or trough), the barrel, for the briefest of moments, is completely stationary, allowing a bullet that exits at that exact moment to move straight ahead, although not directly in line with the barrel's at-rest position prior to firing.
If, on the other hand, the bullet exits the barrel at a point in time in which the barrel is whipping or moving rapidly between the peak and valley positions of the muzzle, the resulting shot dispersion will be greater.
Historically, virtually the only way to control or adapt to the barrel vibrations that affected the accuracy of a rifle was to custom load the ammunition until a correct combination of cases, bullets, primers, powders, seating depths, etc. could be found that would allow the rifle to shoot in tight, consistent groups. It is known that, in addition to affecting the accuracy of the rifle in other ways, the internal ballistics of a given cartridge affect its dwell time in the barrel, i.e., the time it takes for the bullet to exit the barrel after ignition. By experimentally matching the dwell time of the bullet to the barrel's frequency, the best ammunition load for a particular firearm may be found.
Unfortunately, because the best ammunition loads for purposes of barrel harmonics can differ significantly even between otherwise identical rifles of the same model, complicated experimental techniques for determining the optimum internal ballistics of the ammunition must be performed for each individual rifle. The hand loading techniques and firing tests required for this determination are time consuming and hazardous, and require experience and the purchase of expensive equipment.
More recently, various devices have been marketed which, instead of formulating an ammunition load to match the harmonics of the barrel, attempt to tune the harmonics of the barrel to match a given ammunition. One type of device heretofore known in the art uses an adjustable damper or pressure bedding point which purportedly allows the shooter to find a “sweet spot” for damping the vibrations of the barrel that are affecting accuracy. Other tuners work by using an adjustable weight on the muzzle to alter the length of the resonant portion of the barrel.
Unfortunately, although some success has been achieved with these prior devices, the prior devices typically are attached to, and project a significant distance from, the forward end of the barrel so that the prior devices are prone to damage, present a significant obstruction on the end of the barrel, are prone to easily becoming out of tune, must be frequently retuned, and obstruct the use of a flash hider, suppressor, recoil compensator, or other external device on the end of the barrel which could further improve the accuracy of the barrel and/or provide other benefits.
Consequently, a need exists for an improved barrel harmonizing assembly which (a) will provide significantly greater accuracy, (b) will be inexpensive and easy to use. (c) can be used on any type of rifle, (d) does not extend from the forward end of the barrel, and (e) will not prevent or interfere with the use of flash hiders, suppressors, recoil compensators and other external devices which can also be used to improve the accuracy and/or operation of the firearm.